Mechanical properties of native and decellularized reproductive tissues: insights for tissue engineering strategies.

Understanding the mechanical properties and porosity of reproductive tissues is vital for regenerative medicine and tissue engineering. This study investigated the changes in Young's modulus (YM), storage modulus (E'), loss modulus (E"), and porosity of native and decellularized bovine reproductive tissues during the estrous cycle. Testis tunica albuginea had significantly higher YM, E', and E" than the inner testis, indicating greater stiffness and viscoelasticity. Endometrium showed no distinct differences in YM, E', or E" across the estrous cycle or between horns. Ovaries exhibited significant variations in YM, E', E", and porosity, with higher YM and E' in the ipsilateral cortex and medulla during the luteal phase. Decellularized ovarian tissues displayed increased porosity. The oviduct displayed no significant differences in YM or E' in the isthmus, but the contralateral ampulla had reduced YM and E' in the luteal phase. These findings offer valuable insights into the dynamic mechanical properties and porosity of reproductive tissues, facilitating the development of biomimetic scaffolds for tissue engineering applications.

A Review of New Technologies that may Become Useful for in vitro Production of Boar Sperm.

Making sperm cells outside the original testicular environment in a culture dish has been considered for a long time as impossible due to the very complicated process of spermatogenesis and sperm maturation, which altogether, encompasses a 2-month period. However, new approaches in complex three-dimensional co-cell cultures, micro-perfusion and micro-fluidics technologies, new knowledge in the functioning, culturing and differentiation of spermatogonial stem cells (SSC) and their precursor cells have revolutionized this field. Furthermore, the use of better molecular markers as well as stimulatory factors has led to successful in vitro culture of stem cells either derived from germ line stem cells, from induced pluripotent stem cells (iPSC) or from embryonic stem cells (ESC). These stem cells when placed into small seminiferous tubule fragments are able to become SSC. The SSC beyond self-renewal can also be induced into haploid sperm-like cells under in vitro conditions. In mouse, this in vitro produced sperm can be injected into a mature oocyte and allow post-fertilization development into an early embryo in vitro. After transferring such obtained embryos into the uterus of a recipient mouse, they can further develop into healthy offspring. Recently, a similar approach has been performed with combining selected cells from testicular cell suspensions followed by a complete in vitro culture of seminiferous cords producing sperm-like cells. However, most of the techniques developed are laborious, time-consuming and have low efficiency, placing questionable that it will become useful used for setting up an efficient in vitro sperm production system for the boar. The benefits and drawbacks as well as the likeliness of in vitro pig sperm production to become applied in assisted technologies for swine reproduction are critically discussed. In this contribution, also the process of sperm production in the testis and sperm maturation is reviewed.

ATP-Bioluminescence as a method to evaluated microbiological quality of UHT milk / ATP-Bioluminescência como método para avaliação da qualidade microbiológica de leite UAT

New approaches are needed to quickly indicate possible contamination of UHT milk, among them the technique of ATP-Bioluminescence. Therefore, the aim of this study was to compare the results of culture methods with the results of ATP-Bioluminescence technique of 102 UHT whole milk samples incubated at 48, 72, and 168 hours. UHT milk samples were analyzed for the presence of mesophilic and psychrotrophic aerobic microorganisms using Plate Count Agar (PCA), Brain-Heart Infusion (BHI) media and PetrifilmTM Aerobic Count (AC) plates. The ATP-Bioluminescence technique was applied through the Microbial Luminescent Screening (MLS) system. Significant correlations were found between counts of aerobic mesophilic microorganisms on PCA, PetrifilmTM AC, BHI and results of ATP bioluminescence technique (P≤0.05). The ATP-Bioluminescence technique had higher correlation with counting method in PCA than BHI media. At lower pass/fail limits of Relative Light Units (60, 50, 45 and 40 RLU), the number of samples identified as positive increased and statistically agreed with aerobic mesophilic microorganism counts (P>0.05). For the dairy industry, the ATP-Bioluminescence technique may become an important tool that assists the official methods to quickly monitor the microbiological quality of UHT milk though this will likely require a threshold below 150 RLU...

Novos métodos são necessários para detectar de forma rápida a contaminação do leite UAT, entre eles, a técnica de ATP-Bioluminescência. Portanto, objetivou-se comparar os resultados de métodos de cultura tradicionais com os resultados de ATP-Bioluminescência de 102 amostras de leite UAT integral incubadas por 48, 72 e 168 horas. Os leites UAT foram analisados quanto à presença de micro-organismos aeróbicos mesófilos e psicrotróficos usando os ágares PCA, BHI e placas PetrifilmTM AC. A técnica de ATP-Bioluminescência foi aplicada por meio do sistema Microbial Luminescent Screening (MLS). Significantes correlações foram obtidas entre as contagens de micro-organismos mesófilos aeróbios em PCA, PetrifilmTM AC, BHI e os resultados da técnica de ATP-Bioluminescência (p<0,05). A técnica de ATP-Bioluminescência tem maior correlação com o método de contagem em meio PCA que BHI. Quando valores limites de Unidades Relativas de Luz (60, 50, 45 e 40 RLU) foram menores, o número de amostras identificadas como positivas aumentou e concordou estatisticamente com a contagem de micro-organismos mesófilos aeróbios (P>0,05). Para as indústrias de laticínios, a técnica de ATP-Bioluminescência pode se tornar uma ferramenta auxiliar aos métodos oficiais para o monitoramento rápido da qualidade microbiológica do leite UAT, desde que sejam utilizados limites abaixo de 150 RLU...

Evaluation of sperm subpopulation structure in relation to in vitro sperm-oocyte interaction of frozen-thawed semen from Holstein bulls.

The present study examined the relationship between the relative amount of high motile sperm and sperm-oocyte interactions obtained from Holstein bull ejaculates. Post-thaw sperm motility was analyzed using a computer-assisted sperm analyzer system and evaluated to determine the sperm motility subpopulations. Adhesion and penetration of zona pellucida (ZP) and pronucleus formation using post-thawed samples (15 ejaculates form 5 different bulls) with different percentages of sperm in the subpopulation with the fastest and most progressive subpopulation (subpopulation 4 [SP4]) were analyzed. The correlation between the proportion of sperm in SP4 and the number of spermatozoa bound to the zona pellucida (ZBA), the penetration rate, and the rate of pronucleus formation were calculated. A significant (P < 0.05) and positive correlation was found between the number of spermatozoa bound to the zona pellucida, the penetration rate, and the rate of pronucleus formation with the proportion of sperm in SP4 (r = 0.79, r = 0.66, and r = 0.63, respectively). Our results suggest that this specific high motile and progressive subpopulation is positively and significantly correlated with the ability of a thawed bull semen sample to interact properly with the oocyte and its extracellular vestments. These findings emphasize the relevance of analyzing semen subpopulation composition to predict bull sperm fertilizing ability and to select Holstein bulls for breeding purposes.

[Left ventricular function in the acute phase of patients with myocardial infarction randomly treated with 750,000 or 1.5 million units of streptokinase]. / Função ventricular esquerda na fase aguda de infartados submetidos aleatoriamente a 750,000 ou 1.5 milhão de unidades de estreptoquinase.

PURPOSE: To compare the doses of 750,000 and 1.5 million units (U) of streptokinase (SK), relatively to the left ventricular (LV) systolic function analyzed through contrasted ventriculography. METHODS: We included 110 patients with acute myocardial infarction (AMI) within 6h of the onset (mean-age 60 years, 83.6% men), that were randomized to receive 750,000U of SK in 15 min (55 patients), or 1.5 million U in 30 min (55 patients). The study main goal was the comparison between the groups relatively to LV ejection fraction, global and regional shortening, obtained at the fifth day of the AMI. RESULTS: The 750,000 and 1.5 million groups were homogeneous relatively to 15 analyzed variables. Relatively to the main goal of the study, it was found respectively: a) ejection fraction analysis (median): 64% and 60.5% for the total population (p = 0.25, 95% CI -2.7 to 10), 64% and 57.5% for anterior AMI (p = 0.2, 95% CI -3.6 to 16.3), 65% and 65% for inferior AMI (p = 0.99, 95% CI -8.4 to 8.4); b) global shortening analysis: -2.53 and -2.66 for the total population (p = 0.3, 95% CI -0.47 to 0.87), -2.27 and -2.53 for anterior AMI (p = 0.18, 95% CI -0.3 to 1.4), -1.82 and 1.72 for inferior AMI (p = 0.9, 95% CI -0.82 to 0.75); c) regional shortening analysis: anterior AMI -2.6 and -2.67 (p = 0.47, 95% CI -0.7 to 1.5), inferior AMI -2.3 and -2.32 (p = 0.9, 95% CI -0.82 to 0.75). CONCLUSION: The dose of 750,000U was as efficacious as the 1.5 million relatively to LV systolic function, one of the best survival predictors of short-medium and long-term survival post AMI.